Tread for walker



FIG. 1 is a perspective view of a tread for walker showing my new design;

FIG. 2 is a perspective view showing external features thereof;

FIG. 3 is a front view thereof; and the rear view is a mirror image thereof;

FIG. 4 is a right view thereof;

FIG. 5 is a left view thereof;

FIG. 6 is a left view thereof; and,

FIG. 7 is a bottom view thereof.

The broken line showing of a series of wheels in FIG. 1 is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a tread for walker, as shown and described. 